mass defect
mass defect
mass defect
| Noun | 1. |  mass defect - the amount by which the mass of an atomic nucleus is less than the sum of the masses of its constituent particles |
| 单词 | mass defect | |||
| 释义 | mass defectmass defectmass defect
Mass DefectMass defectThe difference between the mass of an atom and the sum of the masses of its individual components in the free (unbound) state. The mass of an atom is always less than the total mass of its constituent particles; this means, according to Albert Einstein's well-known formula, that an energy of E = mc2 has been released in the process of combination, where m is the difference between the total mass of the constituent particles and the mass of the atom, and c is the velocity of light. The mass defect, when expressed in energy units, is called the binding energy, a term which is perhaps more commonly used. See Nuclear binding energy Mass Defectthe difference between the mass of the atom of a particular isotope, expressed in atomic mass units, and the mass number, which is equal to the number of nucleons in the nucleus of that isotope. The mass defect is associated with the binding energy of the nucleons in the nucleus; it characterizes the stability of the particular nucleus. Sometimes the mass defect related to a single nucleon is used; this is called the packing fraction. mass defect[′mas ′dē‚fekt]mass defectmass defectChemistryThe difference in the mass of a polyatomic molecule and the sum of the masses of its constituent particles—i.e., electrons, protons and neutrons. The mass defect occurs because matter is converted into energy (as per Einstein’s E = mc2), which is the energy that binds the nucleus together and overcomes the mutual repulsion between protons. Instrumentation In mass spectrometry, mass defect refers to the positive or negative difference between an ion’s exact mass and the nearest integer. mass defect
Synonyms for mass defect
|
|||
| 随便看 |
|
英语词典包含2567994条英英释义在线翻译词条，基本涵盖了全部常用单词的英英翻译及用法，是英语学习的有利工具。